3个对象（可能为空），以某个属性为key，key重复的话选最高权重的

// 三个奖励是否为存在重复获奖用户， 有则取最高奖励的那个奖励
Map
 
   rewardMap = new HashMap
  
   (3); ActivityNovReward[] rewardArray = {firstReward,lastReward,maxReward}; ActivityNovReward activityNovReward = null ; for(ActivityNovReward reward :rewardArray ){ if(reward == null){ continue; } activityNovReward = rewardMap.get(reward.getUserId()); if(activityNovReward != null){ //存在重复奖励， reward 和 activityNovReward 的用户id 是一样的 if(reward.getRewardAmt().compareTo(activityNovReward.getRewardAmt()) == 1){ // reward 奖励 大于 activityNovReward , 用户 reward 覆盖掉 activityNovReward rewardMap.put(reward.getUserId(), reward); } }else{ rewardMap.put(reward.getUserId(), reward); } }